This invention relates to chromium catalysts to trimerize, oligomerize and/or polymerize olefins. This invention also relates to a process to trimerize, oligomerize and/or polymerize olefins.
Supported chromium oxide catalysts have been a dominant factor in the production of olefin polymers, such as polyethylene or copolymers of ethylene and hexene. These catalysts can be used in a variety of polymerization processes. However, most known chromium compounds must be supported to be catalytically active. Furthermore, most supported chromium compounds are useful only for olefin polymerization. If an olefin copolymer is desired, the polymerization process becomes more complex in that two different monomers must be fed to the polymerization reactor.
Olefin trimerization and oligomerization catalysts are also known in the art, but usually lack selectivity to a desired product and also have a low product yield. However, olefin trimerization and/or oligomerization, if done efficiently, is a process to provide useful olefins. These olefinic products can be further trimerized, oligomerized and/or, optionally, incorporated into a polymerization process.